1. Field of the Invention
The present invention relates to fluid flow control apparatus, and more particularly, to fluid flow control apparatus, which can precisely control slight flow of the fluid.
2. Description of the Prior Art
Fluid flow control apparatus is commonly used in semiconductor manufacturing, in which fluid such as TetraEthOxySilane (TEOS), silane (SiH.sub.4) in a deposition process, or acid HF in an etch process, is required to uniformly and controllably conducted into a reacting chamber.
The arrangement demonstrated in FIG. 1 is an apparatus used in the prior technique, in which gas is injected into the fluid 20 in the container 10 via an input tube 30 inserted into the fluid 20, finally being saturated in the fluid 20. The saturated gas leaving the fluid 20 is then collected by an output tube 32. The gas is further conducted to a mass flow control (MFC) unit 50, and eventually is output to a reacting chamber 80. The apparatus shown in FIG. 1 disadvantageously possesses unpreciseness and nonuniformity on the flow control, and can not be adapted to the control of slight flow of the fluid.
FIG. 2 shows another flow control apparatus in the prior technique. A tube 40 with small diameter is inserted into the fluid 22 contained in a container 10. The fluid 22 is transmitted to a fluid control unit 60, and is then output to a chamber 80. The fluid control unit 60 accompanying the specific tube 40 can greatly improve the uniformity of the flow and its speed. Unfortunately, the amount of the fluid provided by the shown arrangement is limited, and no gas bubble can be tolerated in the specific tube 40, therefore stringing the requirement of the operation for this apparatus. Further, the fluid control unit 60 generally costs much, and its setup requires a great deal of labor.
For the foregoing reasons, there is a need for a fluid flow control apparatus for precisely and uniformly controlling the fluid flow.